Android how to show notification on screen

I've been working on push notifications and I am able to implement it and display it on s开发者_开发知识库tatus bar, the problem I am facing is that I want to display it even if the phone is lock, Under the lock screen where it says ("drag to unlock"), I have seen notifications like that but cant find any example to that.

Example: Just like when you received a missed call , it will show it under the lock button on your screen.

Code:

String ns = Context.NOTIFICATION_SERVICE;
NotificationManager mNotificationManager = (NotificationManager) getSystemService(ns);
int icon = R.drawable.icon_launcher;
CharSequence tickerText = "MyApplication";
long when = System.currentTimeMillis();
Notification notification = new Notification(icon, tickerText, when);
notification.defaults |= Notification.DEFAULT_SOUND|Notification.DEFAULT_VIBRATE|Notification.DEFAULT_LIGHTS;;
CharSequence contentTitle = this.title;
CharSequence contentText = this.message;
Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);
notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);
mNotificationManager.notify(NOTICE_ID, notification);

Create Notification using NotificationCompat.Builder

NotificationCompat.Builder mBuilder =   new NotificationCompat.Builder(this)
            .setSmallIcon(R.drawable.ic_launcher) // notification icon
            .setContentTitle("Notification!") // title for notification
            .setContentText("Hello word") // message for notification
            .setAutoCancel(true); // clear notification after click
Intent intent = new Intent(this, MainActivity.class);
PendingIntent pi = PendingIntent.getActivity(this,0,intent,Intent.FLAG_ACTIVITY_NEW_TASK);
mBuilder.setContentIntent(pi);
NotificationManager mNotificationManager =
                    (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
mNotificationManager.notify(0, mBuilder.build());

Push Notification on locked Screen http://www.hongkiat.com/blog/android-lock-screen-notifications/

Create Notification using NotificationCompat.Builder but make sure to put visibility to public like

NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
        builder
        .setContentTitle("Title")
        .setContentText("content")
        .setSmallIcon(R.mipmap.ic_launcher)
        .setVisibility(NotificationCompat.VISIBILITY_PUBLIC);//to show content in lock screen

Have you tried creating the alertdialog with a flag? The flag_show_when_locked should do the trick. Please refer to this thread, you should find a more detailed answer here. Android Lock Screen Widget

I fixed this by adding this line to notification builder

builder.setOngoing(true);

It will also make notification not cancelable by user, but it solves the problem.

Credits to: Marian Klühspies (link)

The notifications you have seen may actually be widgets placed on a custom widget host lockscreen.

If you look at the android platform source code for InstallWidgetReceiver as late as 4.4.3 here:

https://android.googlesource.com/platform/packages/apps/Launcher3/+/master/src/com/android/launcher3/InstallWidgetReceiver.java

You will see this note by the author:

/** * We will likely flesh this out later, to handle allow external apps to place widgets, but for now, * we just want to expose the action around for checking elsewhere. */

And you can see that InstallWidgetReceiver.java is in fact not fleshed out by google in the same way as InstallShortCutReceiver.java is. So it seems at least up to 4.4.3 you cant add widgets to the native lock screen in the same way that you can for example add a shortcut to the homescreen using InstallShortCutReceiver.

Unless you build your own lockscreen app as a widget host and the user installs in lieu of the native you may be out of luck using a widget.

Another approach however is to just us an activity that sets getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);

This will display your activity whether the screen is locked or not. Dismissing this activity when the screen is locked will display the locked screen.